Resolution: Can you see individual eyelashes and lines on the lips (when zoomed in)? I am not necessarily going to draw every last hair but I can’t create a likeness if the images are vague. The more detail that’s visible, the better.
Light: Good quality daylight is essential. And – I hate to keep giving you rules but – please don’t send me a portrait in silhouette – honestly, this happens a lot!
Permission If somebody else took the photographs you are sending, please make sure you have their permission for me to recreate them.
Finally: I am not judging your skills as a photographer. Just send me a few images and we’ll take it from there.